Now many of these add-ons will slow down Firefox very slightly so I would nottryto download them all - and remember - the downloads will not take effect until you restart the browser.
So go forth, friends, and use this new info to either make the switch or squeeze a better deal out of your current provider -- just remember, no matter how hard you try, you're just not gonna be able to get that unlocked GSM phone to play nice with Sprint or Verizon.